The present invention relates to a vane pump for supplying oil to sliding contact portions of an internal combustion engine, a variable valve actuating apparatus or other apparatus.
A vane pump of such a type is disclosed in a patent document: JP S60-102488U. This vane pump is fixed to a front end of a cylinder block of an internal combustion engine. The vane pump includes: a pump housing made up of a housing member and a pump cover closing an open end of the housing member; a rotor received rotatably in the housing and arranged to receive rotational force through a drive shaft from a crank shaft; and a plurality of vanes received, respectively, in slits formed radially in an outer circumferential portion of the rotor and arranged to slide radially in the slits, respectively. The vane pump further includes a cam ring disposed around the rotor with a predetermined eccentricity with respect to the rotor. The forward ends of the vanes are arranged to slide on the inside circumferential surface of the cam ring and to define pumping chambers each varying the volume with rotation of the rotator for pump action.
The drive shaft includes an engaging portion having two flat outside surfaces, and the rotor includes a center engaging hole having two flat inside surface and engaging with the engaging portion of the drive shaft to transmit rotation from the drive shaft to the rotor.